Transmission line construction begins in Arizona’s Sunbelt

Construction has begun on the 3.2 GW, 500 kV, 125-mile, $389 million Ten West Link transmission line from Arizona to California. The cornerstone ceremony was attended by Vice President Harris, Home Secretary Deb Haaland and Energy Secretary Jennifer Granholm.

The vice president noted that the US’s 500,000-mile network “is in dire need of an upgrade.” This is all the more true as the IRA subsidies are designed to spur mass development of solar and wind power. Compared to the 1,000 GW of wind and solar and 420 GW of storage in the national pipeline, a $400 million transmission line is indeed a small thing for the vice president to inaugurate, and the tone of that sentence was appropriate.

In the first 11 months of 2022, only 888 kilometers of high-voltage power lines were built, less than half the number of 2021. And 73% of the total transmission additions last year were 230 kV or less, with the remainder being mostly 345 kV. While the maximum renewable energy capacity pipeline can be described as 1,000 GW, FERC’s November 2022 Energy Infrastructure Update finds that only 3,338.9 miles of transmission projects have a high probability of being completed by April 2025. At least there is a shift to 500kV and above of this pipeline to almost half the total.

The Biden administration’s funding for the transfer has so far been insufficient, with the most recent major announcement being $13 billion approved in November. In the third quarter of 2022, only $478.7 million worth of transmission projects were approved out of a total of $12.86 billion being considered, according to a report by the NC Clean Energy Technology Center. Funding for the US grid comes from many sources and initiatives, but compare Vietnam’s projected annual spending of $8 billion to $14 billion per year on its grid to the $40 billion that major US utilities planned in 2019 spent and invested. We can also compare this to the Infrastructure Act allocation for the grid — that was $15 billion direct, $12 billion in credit powers spread out from 2022 to 2026.

In November, Arizona approved the termination of a much larger line, the $8 billion, 525 kV, 550-mile, 3 GW SunZia transmission project, along with the 3.5 GW SunZia Wind farm in New Mexico it will power – both privately funded. Construction is slated to begin mid-year, with final approval coming in April from the Bureau of Land Management (BLM) — but the first permit was in 2015, a span of eight years. The third major new line in Arizona will be the Southline Transmission Project, also in the works since 2015, going to New Mexico at around 1 GW, 345 kV and 240 miles.

In the case of the Ten West Link, the BLM granted approval in 2019 but eventually approved construction to begin in July 2022. Concerns were raised, including the military, Native American land, recreational areas, and the Kofa Wildlife Refuge. The Bureau is currently considering 64 onshore utility-scale renewable projects consisting of 41 GW of generation capacity and associated transmission.

Arizona has solar resources almost as good as the high-altitude desert of north-central Mexico that it borders. It is the sunniest place in the US with a global horizontal irradiance of over 6 kWh per square meter in the southern part of the state. That means 50% more power generation per module than in the US states “second from the top” like Pennsylvania, Ohio and Illinois.

This band of high irradiance extends into Southern California, South

New Mexico and East Texas. Looking at this, it is obvious that the US needs a Chinese-style development of UHVDC lines across its southern border, from California through Texas to Florida and then north of Florida along the coast, for the nation as a whole to do so can use resource. As an added bonus, the three-hour time zone difference between the west and the east would mitigate the “duck curve” significantly.

As for the wind, it has its own well-defined region with a +50% performance, namely the pillar that stretches north from Texas to the border with Canada, with an average wind speed of 6 meters per second instead of 4. Adding Put the two regions together and what the US energy transition needs is a T-shaped UHVDC superhighway with Texas in the middle. This may sound silly and simplistic, but similar things are being done in the world’s largest power grid, China, which we noted last week spent over $500 billion on the power grid last year.

In China, this “western desert wind solar, eastern demand center” paradigm is being pursued in the form of several hundred GW wind-solar complexes – a total of 455 GW to be developed under a program by 2050. If the US wanted to, they could do the same, and since solar and wind resource patterns are not going to change suddenly, it is inevitable that this will happen, at least on a limited and piecemeal basis. As for the transmission pipeline mentioned above, about 40% of its lines were built with “high probability by April 2025” in the Western Interconnection, and another 40% in the MRO grid, ie the wind corridor that stretches north of Texas.

Internal US development continues to be hampered by the US’s grid of separate states, planning permissions and semi-separate grid networks. The Western Interconnection, Texas and the rest of the country form three semi-interconnected networks, and apart from Texas, the other two groupings are internally fragmented in terms of policy and planning. Texas is the least connected part of the national power grid when it should become the most connected. The IRA’s funds for transmission are routed to various individual utilities rather than to a federal network.

One way to facilitate the development of a national wind-solar base in the “western desert” would be to simply build it in northern Mexico near the border. In June 2022, the Mexican government inked deals with US developers for 1,854 MW of wind and solar capacity, to be sold primarily to US customers across the border.


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